Ted Hughes wrote:Chelsea sometimes now play a midfield 'diamond' when they use 2 strikers so you could sort of call it 4-4-2 but I don't. Mourinho often played 4-3-3 especially when Robben was available but I would describe Ancelotti's system as 4-1-2-1-2 when Anelka & Drogba play & they user also various 4-3-3 type formations. Although I haven't particularly studied them this season, I wouldn't say we see 4-4-2 that often with Chelsea.
To me a diamond is still 442.
In fact I'd say it's a mode modern 442 as it allows the very in vogue "dm" to be played. It's also my formation of choice for my under 11's so it must be good.